Chapter 9, Mishnah 7 - the final mishnah of the chapter. In fact it contains two separate mishnayos: the first continues the previous discussion and deals with the status of onions and the like that grow in a field belonging to a non-Jew, and the second deals with an entirely separate question - the tumah status of Terumah that was replanted in the ground.
The first part: onions in a non-Jew's field:
The case is a field whose owner is a non-Jew, and he replanted onions that had been taken from that same field without any tithes having been separated from them - and this is indeed the way of non-Jews, who do not separate tithes and are not commanded to do so at all.
Even in a case where the onions had already reached the completion of their processing, and for that reason would have been forbidden to be eaten as a casual snack, the mishnah nevertheless rules leniently: the growths that sprout from such replanted onions are entirely permitted, and a Jew who weeds in the field together with the non-Jew may eat from them as a casual snack. The restrictions set down in the previous mishnayos do not apply in this scenario.
The wording of the mishnah speaks of a Jew weeding in a non-Jew's field among "chasiyos" - a general term for foods of this type: onion, garlic, leek and the like. Even though the non-Jew's produce is tevel and requires tithing, and even if he planted them after they had reached the completion of their processing and had become forbidden as a casual snack, the Jew may nevertheless eat from the new growths as a casual snack.
Two assumptions underlying the mishnah:
The mishnah is teaching something significant here, for it is built upon two assumptions that are themselves subject to dispute:
The obligation of tithes on a non-Jew's land: There is a dispute as to whether produce that grows on land owned by a non-Jew in Eretz Yisrael is obligated in tithes. Our mishnah follows the opinion of Rabbi Meir, who holds that even if a non-Jew holds a plot of land in Eretz Yisrael in his ownership, the produce remains obligated in tithes. The halachic term for this: a non-Jew has no acquisition in land to release it from tithes - there is no way for a non-Jew to acquire land in a manner that would exempt its produce from the obligation.
Completion of processing by a non-Jew: Even if the crop is obligated in tithes, there is a separate dispute - whether a crop whose processing was completed by a non-Jew is obligated in tithes, or whether the obligation is simply not relevant to it. This is comparable to a field owned by hekdesh, where the Temple treasurer completed the processing of its crop - there the crop is exempt from tithes forever. In a similar vein, some say that since at the moment of the completion of the processing the owner of the crop was a non-Jew and there was no obligation to tithe, it never again becomes obligated in tithes.
The mishnah teaches that even if you hold that produce of a non-Jew's land in Eretz Yisrael is obligated in tithes, and even if completion of processing by a non-Jew does not exempt - even so, the Sages did not decree in this scenario. When the non-Jew took onions that had reached the completion of their processing and replanted them, the growths that sprout from them are permitted to a Jew as a casual snack.
The second part: Terumah seedlings that were replanted:
Here the mishnah moves to a different subject: the tumah status of a Terumah plant that is set in the ground. The mishnah takes an extreme case - taking a Terumah plant and replanting it in the earth.
Let us illustrate: a person uproots green onions from the ground, properly separates his Terumah and designates a particular green onion to be Terumah. Afterward that onion becomes tamei. Now it is designated for kohanim, but because of its tumah the kohen cannot eat it. What will be if he replants it in the ground?
Why does the tumah lapse?
The answer is that the status of tumah simply dissipates. Once the green onion is returned to the ground, it loses the status of food and reverts to being a plant, and plants do not become tamei at all. Only four categories of things are susceptible to tumah:
Adam - human beings.
Keilim - utensils.
Ochlin - foods.
Mashkin - certain liquids.
The green onion is a food, but once it is planted in the ground it becomes a plant and is no longer food, and therefore it cannot be tamei, and the tumah dissipates.
This is comparable to a bowl that became tamei and then broke in two: since it is no longer a functioning utensil, it becomes tahor, and if one reattaches the pieces - assuming it is not a glass or metal bowl, where there are rabbinic considerations, but a simple wooden bowl - the reconstituted bowl remains tahor. So too here: the plant that was returned to the ground becomes tahor.
The decree of the Sages:
Nevertheless, the Sages imposed a restriction, so that one would not be able to bypass the system by replanting all of his tamei Terumah produce until the tumah lapses. This concern runs along the same line as the general theme of the chapter: that people might hold on to tamei Terumah and come to eat it inadvertently. The Sages therefore ruled that it remains forbidden.
These are the words of the Mishnah: "Shesilei terumah shenitme'u ushesalan" - edible plants that were detached from the ground, designated as Terumah and became tamei, and now he replanted them. "Taharu mil'tamei" - their capacity to transmit tumah has been removed, and they are tahor once again, since they have ceased to be food, as explained. "Va'asurin mile'echol" - the status of Terumah has not lapsed from them, and rabbinically they are treated as tamei Terumah that may not be eaten, "ad sheyagom" - until he cuts off all the greenery that grew there. Whatever grows the second time will be permitted to a kohen as tahor Terumah.
The word "yagom" has already come up several times in this Order. In the other places it refers to trimming a tree, that is, cutting it down to within a handbreadth of the ground, and that is its usage here as well: he takes the green onion and cuts off all the greenery that grew above, and whatever grows the second time becomes permitted - still Terumah, but tahor Terumah. Until he cuts it, the Sages require that the edible greenery remain tamei by rabbinic law.
Rabbi Yehudah's dissenting view:
Rabbi Yehudah disagrees, and according to the Bartenura he disagrees stringently: "Ad sheyagom v'yishneh" - one cutting of the edible green portion is not enough. He must cut off the green portion, allow new greenery to grow, and cut it a second time; only what grows the third time may be eaten. The halachah does not follow him, but rather the first Tanna, that one cutting suffices.
A closing note on the chapter as a whole:
Before we conclude, it is worth noting a point that ties all of this back to the chapter as a whole. The central theme of the chapter was produce grown from Terumah, where the Sages sought to create a negative financial incentive that would keep kohanim from holding on to Terumah that had become tamei. A kohen whose Terumah wheat had become tamei might well leave it sitting on the shelf until planting season, sow it again, and in effect "launder" his tamei Terumah - after all, whatever comes up out of the ground receives a fresh start on the Torah level, and in this way he recoups his financial loss.
The Sages did not want this, out of concern that the kohanim would leave the tamei wheat lying around in their kitchens and eat it inadvertently, violating a Torah prohibition. They therefore ruled that there is no point in keeping it, since whatever grows from the ground will once again be Terumah.
Now, our Mishnah rules that the tumah status of that Terumah is washed away once it is replanted, and at first glance this seems inconsistent with the opening of the chapter. For according to this, a kohen holding tamei wheat that is unfit to eat will simply wait for planting season, sow it, and what comes up will indeed be Terumah - but pure Terumah, fit to be eaten. He comes out ahead and recovers exactly what he lost. If what emerges from the ground is not considered tamei by rabbinic law, we have removed the very heart of the rabbinic requirement to treat produce grown from Terumah as Terumah.
Let us sharpen the point: until now we spoke of Terumah that returns to being Terumah, but combining our Mishnah with the earlier ones yields the following: one who plants tamei Terumah gets produce from the ground that is still Terumah, but pure Terumah. If so, it would not be at all unreasonable for a kohen to leave his tamei Terumah sitting on the shelf until planting season, since in the end he will receive pure Terumah and eat it, which is precisely what he wanted to do by eating it in the first place. If so, what did the decree of the Sages accomplish, and how can it be effective at all?
The answer is that the decree is effective for two reasons:
The low value of a Terumah crop: a kohen fortunate enough to own land would be foolish to raise a crop of Terumah, for if he sows his fields with Terumah wheat, the entire crop that grows that year will be Terumah. Terumah wheat is worth only a fraction of the value of ordinary wheat, since ordinary wheat can be sold to anyone and eaten by anyone, whereas Terumah wheat may be eaten by kohanim alone.
The restriction of purity: moreover, only kohanim who are tahor may eat it. The kohen himself will be unable to eat from it at certain times, and so too his wife when she is temei'ah. The produce therefore turns out to be highly restricted and of little value.
Given all this, it would be foolish for the kohen to hold on to his tamei wheat and sow it, and so the rabbinic enactment remains effective even though what comes up out of the ground remains pure.
In summary: in this Mishnah we learned two matters. In its first part - a Jew weeding in a gentile's field of "chasiyos" may eat casually from the plants that were replanted, even though the Mishnah holds that produce of a gentile's land is obligated in tithes and that the completion of processing by a gentile does not exempt it. In its second part - Terumah seedlings that became tamei and were replanted are purified from conveying tumah, since their status as food has lapsed, but by rabbinic law they may not be eaten until one harvests them; and Rabbi Yehudah is stringent, requiring "until he harvests and harvests again," and the halachah does not follow him. We also examined how the decree of the Sages remains effective throughout the entire chapter, even after the tumah lapses.
With this the chapter concludes, and in the next chapter, chapter ten, we will begin an entirely new topic.